SD Card Sizes report
Secure Digital (SD) card is a new generation of the memory device based on semiconductor flash memory. Because of its small size, fast data transmission speed, large capability, and other excellent characteristics, it is widely used in portable devices such as electronic dictionaries, mobile phones, Digital cameras, car navigation systems.
When choosing a flashcard, the first thing to consider is determining what type of card your device needs, which can usually be found in the instructions for use or on the manufacturer's website. Manufacturers usually specify the SD standard required by the device.
Nowadays, there are only two main sizes of Secure Digital (SD) Card in general use – the (Full-size) SD Card and the Micro SD Card. SD cards and microSD cards use the same standards: SD, SDHC, SDXC, and SDUC and microSD, microSDHC, microSDXC, and microSDHC. The following post explains more details about the SD card.
SD Card Basics
The structure of SD cards can ensure the security of digital file transmission, and it is easy to reformat, so it has a wide range of applications. There are many brands of SD cards on the market, such as SANDISK, Kingmax, Panasonic, and Kingston.
But not all SD cards are the same, and different devices require different types of flashcards. When shopping, you need to consider the different SD card's performance: speed grades, physical dimensions, and capacities.
SD Card Types and Sizes
SD cards come in different sizes. You will find standard SD cards, miniSD cards, and microSD cards that are incompatible with each other. In other words, a miniSD card reader won't work with microSD cards.
- full-size SD cards: 1.26 x 0.94 x 0.083 inches (32 x 24 x 2.1 mm). Most digital cameras for sale today still use standard SD cards. They have the familiar "cut corner" design.
- miniSD cards: 0.85 x 0.79 x 0.055 inches (21.5 x 20 x 1.4 mm). MiniSD cards aren't too common today.
- microSD cards: 0.56 x 0.43 x 0.039 inches (15 x 11 x 1 mm). It is the smallest size of SD card. These cards are used in most cell phones, smartphones, and drones that support SD cards. They’re also used in many other devices, such as tablets.
| SD Card Size | Dimensions | Weight |
|---|---|---|
| full-size SD card | 32 x 24 x 2.1 mm | 2g |
| miniSD card | 21.5 x 20 x 1.4 mm | 0.8g |
| microSD card | 15 x 11 x 1 mm | 0.25g |
SD Card Speed Grades
The data transfer speed of each SD card is different. Therefore, the SD Association divides different levels according to the minimum sequential write rate -- the slowest speed at which data can be put onto the memory chip in a structured. The rate of each level is measured by how many MBs are transmitted per second, and the unit is MB/S. The SD Association defines three speed classes: Speed Class, UHS(Ultra High Speed) Class, and Video Speed Class.
- Four different speed classes: 10 (10MB/sec), 6 (6MB/sec), 4 (4MB/sec), and 2 (2MB/sec).
- Two Ultra High Speed (UHS) speed classes, 1 (10MB/sec) and 3 (30MB/sec). They are designed for professional use, but you will find them on most of today’s SD cards.
- Five Video Speed classes: V90, V60, V30, V10, and V6.
| SD Card Speed Grades | Read/write speed | Use for | |
|---|---|---|---|
| Speed Class | Class 10 (C10) | 10MB/sec | fastest, suitable for "full HD video recording" and "HD still consecutive recording" |
| Speed Class | Class 6 (C6) | 6MB/sec | suitable for "high-definition video recording" |
| Speed Class | Class 4 (C4) | 4MB/sec | suitable for "high-definition video recording" |
| Speed Class | Class 2 (C2) | 2MB/sec | slowest, suitable for "standard definition video recording" |
| UHS(Ultra High Speed) Class | UHS Class 1 (U1) | 10MB/sec) | professional use |
| UHS(Ultra High Speed) Class | UHS Class 3 (U3) | 30MB/sec) | professional use |
| Video Speed Class | V90 | 90MB/sec | 8K video recording |
| Video Speed Class | V60 | 60MB/sec | 4K video recording |
| Video Speed Class | V30 | 30MB/sec | HD/Full HD video recording |
| Video Speed Class | V10 | 10MB/sec | 720p/1080p video recording |
| Video Speed Class | V6 | 6MB/sec | 720p/1080p video recording |
SD Card Capacity (Storage Size)
Like USB flash drives, hard drives, solid-state drives, and other storage media, SD cards can have different amounts of storage. Standard SD cards and microSD cards have four SD standards, one for each storage size. The four SD standards are:
- SD or SDSC (Secure Digital Standard Capacity): Maximum storage of 2 GB.
- SDHC (Secure Digital High Capacity): More than 2 to 32 GB of storage.
- SDXC (Secure Digital Extended Capacity): More than 32 GB to 2 TB of storage.
- SDUC (Secure Digital Ultra Capacity): More than 2 to 128 TB of storage.
| SD Standard | Storage Size |
|---|---|
| SD or SDSC | Up to 2GB |
| SDHC | 2GB to 32GB |
| SDXC | 32GB to 2TB |
| SDUC | 2TB to 128 |
The SD standard represents a timeline of SD card development, with newer cards having higher storage capacities and faster speeds. SDUC was released in June 2018, and it may take some time for SDUC cards to hit the market and gain widespread industry usage. Hardware devices on which flash cards are installed are backward compatible, which means you can use older standard flash cards in devices that support newer standards such as SDXC.
Summary
MicroSD cards are smaller SD cards, the biggest difference between the two is size. MicroSD cards are more versatile these days because they often come with SD adapters that allow you to use microSD cards with devices that only support SD cards. When buying an SD card, you need to check what your device supports and consider the right speed class, size, and capacity for your needs.
